As a photosensitive unit, there has been proposed a known photosensitive member cartridge including: a photosensitive member frame; and a photosensitive drum and a cleaning unit, which are supported by the photosensitive member frame.
An electrostatic latent image is formed on a surface of the photosensitive drum. The electrostatic latent image is visualized by supplying toner and is formed into a toner image. The toner image is then transferred to a sheet.
Paper dust may be adhered to a surface of the photosensitive member at a time of transferring the toner image to the sheet. The cleaning unit serves to remove the paper dust adhered to the surface of the photosensitive drum. The cleaning unit includes a primary cleaning roller, a secondary cleaning roller and a sponge scraper.
In the cleaning unit, the primary cleaning roller is brought into contact with the surface of the photosensitive drum. The paper dust adhered to the surface of the photosensitive drum is captured by the primary cleaning roller, and the captured paper dust is then passed to the secondary cleaning roller from the primary cleaning roller. The paper dust passed to the secondary cleaning roller is scraped off by the sponge scraper and is then stored in a paper dust storage chamber that is provided inside the cleaning unit.
A spring presses the cleaning unit toward the photosensitive drum in order to bring the primary cleaning roller into contact with the photosensitive drum uniformly.